US2936794A - Picker stick check straps - Google Patents

Description

May 17, 1960 v H. J. sHlvELl. ETAL 2,936,794

PICKER STICK CHECK STRAPS Filed March 20, 1958 2 Sheets-Sheet 1 May 17, `1960 H. J. sHlvELl. ETAL 2,936,794

PICKER STICK CHECK STRAPS 2 Sheets-Sheet 2 Filed March 20, 1958 United States Parent OJ" PICKER STICK CHECK STRAPS Homer J. Shivell and Weymouth F. Dow, Kingsport, Tenn., assignors to Slip-Not Belting Corp., Kingsport, Tenn'.

Application March zo, 195s, serial No. 722,679 Y 19 Claims. (ci. 139-165) This invention relates to a device'for checking the motion of picker sticks in looms. v

For many years, it has been standard practice in looms to use a belt, known as a picker check strap, to check the motion of the picker stick when ithas caught'the shuttle and moved back to the position inwhich it is ready to throw the shuttle. `In some cases, such straps have their ends overlapped and secured to a bracket on the loom. The opposite sidel ofthe resultingloop,v or belt, passes between ngers which are staggered slightly to produce a slight bend in the loop and at least one of the fingers is adjustable to vary the amount of oset and tension applied to the loop, Whentthe loop is drawn between the fingers it is subjected to some frictional drag on the lingers. In other cases, the strap is formed into an endless loop and is held'by a bracketwhich exerts in this same way a bending andfrictionalf resistance. The loop, in either case, isshorter than the amplitude of the picker stick stroke. y

. It is very important that the'checking of the picker stick be exactly right. If the'shuttle is not,stopp'edrat the correct position by the picker stick and its checking device, or if it is caused to jurnp alittle or is-in any way deflected from its proper path or direction, itA is likely to cause a defect in the Woven goods, which will reduce its value and sale price. f

Therefore, very skillful adjustment and maintenance of the checking device isrequired. Often aloom which was running perfectly on ,'Eriday afternoon may run badly when tirstbrought back `into operation on Monday 2,936,794 Pdtented May 17, 1960 ice ' providedany means for maintaining theaccurately bal'- anced drag required for properly checking the picker stick. The present invention lls this longjfeltneed.

lIn addition to adjusting the drag andlimiting the positions of the checking device, `the present inventionA also provides a simple adjustment of thelength of the check strap and of its orientation to the stick when the stick is checked. It also permits use of check straps in such a way as to reduce wear and secure maximum servicelife.

The invention also facilitates installation of the checking device on looms of various sizes and types and adjustment of the devices to special and even peculiarrequirements. Installation is simple, and ,only a moment is required to adjust the balance. Once adjusted, the device will operate for indenite periods without attention.

Another advantage of the present invention is that the binder facings in the shuttle box and the terminal bumpers are subjected to much less Wearl because the picker check- -ing device does its job of slowing down the shuttle much better. For the same reason, the shockY and vibration imposed on the loom is much less than Whenother checking devices are used and shuttle jumping can be completely eliminated. v 'In contrast to the conventional checking devices which require dicult and costly adjustment after a loom has tion material which is unaffected by shutdowns and will continue to ,operate for long periods, whether operation is continuous or with alternate idle periods.

We have now found that the Vlife of'a check strap'V can v be increased and an improved action attained ifvthe action of a leather strap is combined with a mounting ywhich can yield by slipping on an anti-friction bearing.

morning, and after being properly adjustedfto its new condition will have to be readjusted as the leather straps limber up. This is troublesome and expensive. V74Other materials than leathers and other'types ,of checking vd'ev i'ces also have been suggested, but nothingelse has-been ableto meet as fully the need for absorbingrthe repeated shocks of the shuttle impacts and for checking the throw of the pickervstick without bounce `or deflection of theshuttle. Y t l The shuttle is thrown back and forth by the picker stick at high speed and with relatively high power across the loom and is sensitive toany'variations whichpmay change, even slightly, the length or direction` of `travel ofthe shuttle. Proper check strap action is a prerequisite to weaving 4Erst-quality fabrics and any variations .in the action of the check strap arefaptto Vproduce defects in the fabric. lIt has Jlong been known lthat more accurate t A.control has been needed to stop the action ofthe picker stick at just the right place in the lay and that, for lack of such control,J expensive shut-downs .and imperfectly woven fabrics` have been the commonexperience. Improvements toward this end have been made by designing check straps of dimensions better adapted to their proper functioning or of better form, e.g., conical belts and endless belts. Il have'now shown, bythe present invention, that perfect weaving alsov requires accurate tension adjustments on bothsides of the path of the The loading of the bearing is adjustable y'togive afresistance to slidingwhich balances theY resistance `of the strapr to flexing and pulling through thek bracket:

Thel deviceV of the present 'invention uses a checking strap which is engaged by the picker stick as it nears g each end of its travel, but, unlike prior checking devices,

picker stick, so that the Ichecking action is both accurate most of the force for slowing down the shuttle is provided by a bearing of vanti-friction material and an ad.- justable means for pressing it against a smooth slide par.- allel to the path of the picker'stick. 'The check strap is secured at spaced points to a member which is slidable by reason of said bearing, i.e., on'the bearing or meansl carried thereby if the slide is fixed on .the loom, or on the slide if the bearing is xed on the loom.Y The strap is clamped thereon at each end adjacent the Vpath of 4the stick and projects across 'and approximately perpendicular to the path of the stick, and the strap bctween these end vportionsis yieldablyrheldby a tension'- iug device for imposing a drag balanced against that of the anti-,friction bearing.v This tensioning device may comprise the usualcheckA strap bracket consisting of staggered fingers adapted, by bending the strap .around` them, to exert both a'r'esistance to rebending and a fric'- tion` due to the resilientpressure of the strap on the fingers.A The resulting vdrag on the' strap vsupportsit i at each side. f

Because of the use of anti-friction bearing material, the

checking device immediately yields to the impact, avoiding any serious shock, and because it slides as it checks Ythe impact, any heating due to absorption of kinetic-energy is distributed along the length of the strap and slide, respectively, with no part being overheated so as to cause rapidV deterioration. The anti-friction material is advantageously one which is substantially uniform to an yappreciable depth, and advantageously substantially dry and one in which its characteristics to relative sliding remain stable with ordinary atmospheric changes, especially humidity and temperature. VThe --clamped ends of the strap are easily adjusted lengthwise lof the strap to give the exact length of strap required for perfect checking action. This structure allows the picker stick to travel back and forth in its plane of movement without any stress or strain which would 'twist it or cause it to jump.

In this specication and accompanying drawings, several embodiments of my invention and suggested modifications thereof are shown and described, but it is to be understood that these illustrations are not intended to be exhaustive nor limiting of the invention. On the contrary, the various modications are given for the purpose of illustration in order thatothers skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify and adapt it in various forms each as may be best suited to the conditions of a particular use.

In the drawings:

Figure 1 s a side elevational view of the lay and picker Figure 3 is a plan View similar to Figure 2 showing Y the checking device being actuated by the picker stick;

Figure 4 is an enlarged perspective view of a checking device incorporating the present invention and showing the manner of adjusting the ends of the check strap;

Figure 5 is a front elevational view of the checking device partly in section to show the construction of the bearing element for producing a predetermined constant drag on the slide rod of the checkingV device;

Figure 6 is a transverse sectional view taken on line 6-6 of Figure 5 to show the manner of compressing the packing to adjust the drag on the checking device.

Figure 7 isa view similar to Figure 6, but showing a split nylon sleeve in the bearing for applying apredetermined drag on the checking device;

FigureS is a perspective view of a checking device of modified construction and showing the ends of the check strap directly connected to the ends of the slide rod;

Figure 9 is a longitudinal sectional view of a bearing checking device of the invention is shown applied to the lay 12 of a loom for weaving fabric. In such looms, the shuttle 13 is thrown across the loom in the shed between the warp strands by the picker stick 14. Picker stick 14 is movedfrom the position illustrated in full lines to the position illustrated in dash lines in Figure l with a snap action by a driving mechanism (not shown) to propel the shuttle 13. After the picker `stick 14 has thrown the shuttle, its forward motion is checked byra check strap 15 of the checking device 16-constituting the subject matter of the present invention. The picker stick 14 is returned to its initial position illustrated in full lines in Figure l by the shuttle 13 striking its upper end and this motion of the picker stick also is checked by the check strap 15 of device 16.

In accordance with the present invention, the check strap 15 may comprise a single or double ply of a suitable material such as leather, or may include an additional wear strip as illustrated in Figure 8, or may be formed of a composite leather strap as illustrated in Figure l1.v In any of the strapV constructions the grain and hair side of the inner ply is positioned at the inside for engagement by the picker stick 14. In the embodiment of the invention illustrated in Figures l to 6, the ends of the check strap 15 are folded inwardly towards each other to form a loop and the ends are attached to the blocks 17 and 18 by means of bolts `19. The blocks 17 and 18 are adjustably mounted on a slide bar 20 in the form of a rod having a smooth peripheral surface. Rod 20 has threaded ends 21 and 22 which cooperate with tapped holes in the blocks 17 and 18 to adjust the length of the check strap 15 for the throw ofthe particular picker stick 14Y and the blocks are held in adjusted `position on the rod by means of check nuts 23. Thus,v the ends of the check strap 15 are attached to the rod 20 and form a loop .for engagement by the picker stick 14 at each end thereof. VThe ends of the loop may be parallel, but advantageously as illustrated the leather plies of the check strap 15 are so cut that when their ends are folded inwardly the loop will have a generally conical form to provide inclined sides having substantially the same angle as the picker stick 14 when the latter engages the strap.

In accordance with a particular feature of the present invention, the rod 20 of the checking device 16 is mounted to slide ina cylindrical bearing sleeve 24 in a bearing block 25 which is attached to a iixed bracket 26 `on a part of the loom such as the lay 12. As illustrated, the bearing block 25 has a laterally projecting stud 2.7 projecting through a hole in the bracket 26. In some looms, the bearing sleeve 24 projects from the upper end of supporting block 25, as illustrated in full lines in Figure 6, and in other installations the bearing sleeve projects from the lower end of the block, as illustrated in dash lines .in Figure 6, depending upon the position of the Vattaching bracket 26 and stud hole in the particular loom. In any case,l the bearing sleeve 24 is xed and the checking vdevice 16 moves in either direction vrelative tothe `cylindrical bearing sleeve 24 when engaged by thepicker stick 14. Y

The movement of the checking device 16 is controlledr at )one side by'v a bearing element -28 in the sleeve 24 Iwhich produces a constant drag on the rod 20 throughout "a strokeV as it slides in the bearing'sleeve. The bearing element 28 maintains a constant drag on rod 20 under all operating conditions and the amount of constant .drag produced may be initially adjusted for 'a particular loom. As shown in Figures 2 and 3, a tensioning device 29 is attached to the loom for engaging and yapplying a Xed tension vto the check strap 15 at a position opposite the Vcylindrical bearing 24. Tensioning device 29 has `a pair ofs'paced fingers 30 and 31 engagingthe inside face ofthe inner ply of check strap 15 and a iinger 32 engaging the outsideface of the outer ply for producing a fixed resistance to sliding movement' therethrough. The finger 32 is mounted on an adjustable slide 33 which may be locked in position by a nut 34 to .adjust the particular tension applied by the tensioning device'29, Thus, when the picker stick 14 engages the check strap 15 to move it to the left, as illustrated in vFigure 2, Vthe bearing element 28 in sleeve 24 produces a predetermined fixed drag on the rod 20 while the tensioning device `29 produces a corresponding drag on the Opposite Sid@ `of the check strap- As shown'in detail in Figure 5,v the bearingelement 28 in sleeve 24 comprises anti-friction bushings 35 and 36 at eachend and a packing material 37 between the bushings for applyingv the predetermined fixed drag on the` rod 20. The anti-friction bushings 35 and 36 are` of `a kind which operate dry or, -in other words, do not require any added lubricant so that its fcoecient of friction does not vary with the condition of the lubricant. A suitable material for the bushings 35 and 36 is nylon or Teflon which has a low coecient of friction with a steel rod 20, but porous oil impregnated metal bearing bushings can be used.

The packing 37 between the end bushings 35 and 36 is in the form of a series of leather washers having central holes of substantially the same diameter as the outside diameter of the rod 20. The leather washers are soaked in oil for a period of time to completely impregnate the leather after which excess oil is removed as by pressing. The leather washers of packing 37 engage the periphery of rod and produce a predetermined xed drag thereon with a coeiiicientv of friction which remains substantially yconstant ythroughout the life of the. washers. =Overlying the central portion of the packing 37 is 'compression platei 38 actuated by a set screw. 39 for compressing the packing to adjust the dragv produced by the packing. A It has been found that a resilientjplatel 38 of natural ory synthetic rubber is especially advantageous4 as its yielding pressurey permits and maintains a closer adjustment of the dragon thechecking device 16. Thus, the bearing sleeveV 24 requires no lubrication and will produce and maintain a constant uniform dragon the rod 20 which may be adjusted by means of the-set screw 39 and compression plate 38v for the `particular installation. AWhen'once adjusted the set screw 39.is locked in adjusted position by means of the lock nut40. y f

The bearing elements are assembled in the bearing sleeve 24 by rst inserting the nylon .bushing 35 against an annular flange 41 Iat oneend of ythe sleeve 23; inserting the plurality of leather washers" 37 into the sleeve one after the other and finally inserting-the other nylon bushing 36. A metal Washer'.;4 2 `is thenfapplied over the outer face of the nylon bushing 36 and the entire assembly is locked in the sleeve`. 24 by meansof Ya spring clip 43 engaging aperipheral groove 44 inthe sleeve; One form of the invention having now been described inV detail the mode of operation is explained asfollow's: When the picker stick 14 is in the full lineV position illustrated in Figures' l and 2,{the' checking device 16 is located at its extreme left hand @position relative to the bearing sleeve Y2.4. Pickerfstick14 is then'moved by its driving mechanismI from the position illustratediny thefull lines to that illustrated iny dash lines 'in Figure 1'. ,The upper end of the picker stick 14 engages the rearward end of the-shuttle v13' and;y propels it to the opposite side of the loom.y After the shuttle 13 leaves theend of the picker stick 14 the movement of the latter is .checked by the checking device 16. As the end of the picker stick 14 engages theright hand endfof` the check strap'lS the Ymotion of the picker lstickvisV trans'- mitted to the checking-device, 16. which moves as a unit relative to the bearing sleeve'24. .p

yDuring such `relative movement, thefrod` 20 slides 'in theebear'ing sleeve 24 which .produces 'a predetermined fixed drag therefor and the strap opposite the bearing sleeve slides through the tensioning device 29 which'prof duces a` correspondingY drag on 'thefstrapzn'fhe spaced anti-friction bearing bushings 35' and 36 permit freelon- `gitudinal-movement of the rod 20 and prevent it from Icramping while the packing 37 ofleather washers applies a-.centrally located predetermined constant drag on `the .rodbetween the bushings. Such movement ofthe checkingdevice y16 relative to the fixed bearing sleeve 24V is illustratedin Figuresv2-anfd`f3. As the bearing element "z andtensioning dev'icelg29 `are initiallyadjus'ted to videanti-friction'bearing surfaces for the rod 20 at each Y lof further'moditie'd construction.

produce the same drag on the rod 20 and check strap 15, the checking device 16 will move in a straight line and retard the motion of the picker stick 14 without tilting or cramping the checking device or stick. Furthermore, as the force applied to the picker -stick 14 and the drag produced by the checking device 16 remain constant during each pick, the picker stick will be stopped at the same position after each pick. Conversely, the shuttle 13 will produce the same force on the end of the picker stick during its return movement and will be checked by the check strap 15 with the same drag to stop the picker stick in the same position at the other end of its movement after each pick. t

Thus, the picker stick 14 is always properly positioned after each pick to throw the shuttle 13 with the same force and direction. This results in applying the same tension to the weft strand as it pays out from the shuttle. As "a, result shuttle jumping.and irregular movement of the shuttle 13 is eliminated so that the uniform fabric is produced. This result may be depended upon'for all operating conditions and upon start-up after a* shut down as well as during continuous operation of the loom. This uniformity of operation is due to the fact that the vrod 20 of the checking device 16 is supported at spaced points in anti-friction bearings while the drag is applied between thespaced bearings by the leather washer packing 37 and the drag remains constant without variation.

fFigure 7 illustrates a bearing element 28 of modified construction for applying drag on the rod 20. In this modied construction the bearing is in the form of a split bushing 50 of a dry anti-friction material such as nylon which extends throughout the length of the cylindrical bearing sleeve 24. Nylon bushing 50 is slotted throughout its length at 51 to provide spaced edges to adapt it t0 be compressed to a smaller inside diameter. One end of the bushing 50 engages the annular flange 41 in the bearing sleeve 24 and is held in position in the sleeve 24 by a spring clip 43` engaging itsother en d as in Figure 5: IThef nylon bushing 50 has an inside diameter to proend. The central'part of the nylon bushing 50, however, is compressed in the `bearing sleeve 24 to apply a predetermined constant drag. The compression of thecentral portion of the nylon sleeve 50 is produced by a yielding rubber plate 52 at the side opposite the slot 51 which, in turn, is compressed by a set screw 53 threaded in a tapped holo 54 in the bearing sleeve 24. A lock nut 55 is provided for locking the set screw 53 in any adjusted position. Such compression of the split bushing 50 in the `bearing sleeve 24 by set screw 53 tends to contract its central portion into frictional leng-agement with the periphery of the rod 20 with-the force required to produce the pre; determined constant drag. lt has been foundrthat such a bushing construction will produce a predetermined constant drag under all operating conditions. The modified nylon bearing construction illustrated in Figure 7 operates in the same way as the vconstruction illustrated in Figure 5 to check the motion of the picker 'stick 14. As the bearing sleeve 50 produces a predeter# Vmined constant drag on the rod 20 and as the tensioning device 29 controls the movement of lthe check strap 15 the movement of the picker stick 14 and shuttle 13 is uniform under'all operating conditions.

Figure'Seillustrates a picker stick In the construction illustrated in Figure 8, a double ply check strap 61 is provided having short wear straps 62 and 63 at each end for engagement by the picker stick. The ends 64 and 65 of the check strap 61 and wear straps 62 and 63 are pro- `vided with holes and apply directly over the ends of a slide rod 66. The ends of the rod 66 are threaded and` have nuts 67 and 68 at each end for clamping the ends 64 and 65 of the check strap 61 thereto. The length of the check strap 61 may be adjusted byscrewing the Yomlaag device 6o Y 7 nuts`67 and 68 inwardly or outwardly on the rodY 66 and thereby adjusting the spacing of the ends 64 and 65 Vof the checkvstrap 61. Y

In the checking device 60 illustrated in Figure 8, the bearing element 28 for the rod 66 may be of the leather washer type illustrated in Figure or the continuous split nylon bushing illustrated in Figure 7. The bearing sleeve 24 is mounted on a bearing block 25 With a laterally projecting stud 27 as in Figure 4 for attaching the checking device `60 to a bracket 26 on the loom.

The checking device 60 operates in substantially the same way as the check device 16 illustrated in Figures 1 to 6. Checking device `60 isV particularly adapted for use `in looms of the type having an inside check strap bracket with a limited space for the check strap. However, the Wear straps 62 and 63 provide additional stiffness to the check lstrap 61 and provide a separate Wearing surface engaged by the picker stick 14. Thus, only the relatively short back-up straps 62 and 63 are subjected to Wear and may be easily replaced.

Figure 9 illustrates a checking device 70 having a xed bearing block 71 of further modiiied construction for applying a predetermined constant drag on the slide rod 72. The modied form of bearing block 71 is shown applied to a checking device of the type illustrated in Figure 8, but it will be understood that it can be applied'to a checking device of the type illustrated in Figures 1 to V6. As in Figure 8, the checking device illustrated in Figure 9 has a double or single ply check strap 73 of conical form with back-up straps 74 and 75 directly applied on the threaded ends of the rod 72. In addition, plates 76 of a plastic such as nylon, or metal with leather cushioning and reinforcing pieces are provided between the outside ends of the check strap 73 and the clamp nuts 77. These plates 76 provide an additional cushioned stiffness to the portion of the check strap engaged by the picker stick 14.

The rod 72 of the checking device 7i) slides in bearing block 71 adapted to be bolted to the bracket 26 on the loom and having a transverse bore 7 9 of greater diameter than rod 72 and throughwhich the rod extends. The bearing block 71 has counterbores 80 at the ends of the bore 79 to provide an annular shoulder 81. Antifriction bearing bushings 82 and 83 are mounted in the bearing block 71 to bear against the annular shoulders 81 and are locked in place therein by means of snap rings 84. Projecting outwardly from the bearing block 71 is a cylindrical boss 85 having a central bore 86 at right angles to the bore 79. Mounted in the bore 86 of the boss 85 is a nylon bar 87 of cylindrical form which projects in bore 79 to engage its end with the periphery of the slide rod 72 to apply the drag thereon. At the rear of the nylon bar 87 Ais a resilient plug 88v of rubber or the like and beyond the rubber plug is a set screw 89 engaging threads in the bore 86. The threads in the bore S6 ex` 'tend for a limited distance only so that the set screw can never engage the periphery of slide rod 72. Thus, by turning the set screw 89, the end of nylon bar 87 is engaged with the periphery of the rod 72 with predetermined resilient pressure. Set screw 89 is held in adjusted position by alock nut 90.

Also in this construction U-shaped leather washers 911 are provided on the Vrod 72 between the bearing block 71 j and the clamp nuts 77 for attaching the ends of the `check straps 73 to the ends of the rod. The leatherl washers 91v prevent a metal to metal contact of the bearing block 78 with the clamping nuts and thereby serve as a safety device.

The checking device 71 illustrated in Figure 9 operates in the same Way as the previously described construetions except that the bar 87 of nylon, Teflon or other material having good lubricity produces the predetermined drag lon the checking device between the anti-friction bearing bushings 82 and 83. It has been foundthat 'the engagement of the -end of 'the bar 87 with the periphery ofthe steel rod 72 produces a -predetermined constant drag under all,V operating conditions.

' A composite leather strap 92 as illustrated in Figure 11v can be used Vto advantage as al check strap15 in the checking devices illustrated in Figures l and 9. Natural leather comprises an outer hair and grain layer,a middle binder layer and an inner esh layer. In a piece of leather 1A: inch thick the hair and grain is about /g of an inch in thickness, the .middle binder layer is'about 1/32 of an inch thick and the inner flesh layer is about i of an inch thick. The surface of the grain layer is best for wear, abrasion and frictional contact but has only about 5% to 7% of the tensile strength and a limited stretch relative to the esh layer. The flesh layer has 90% to 95% of the tensile strength and can be stretched to a much greater degree than the Vgrain surface. Furthermore, stretching of the flesh layer is an advantage as it Ychanges the position of the fibers from vVertical to horizon'tal. If the grain layer is stretched to the limit of the liesh layer it is apt to crack.

VThe composite check strap95 having better Wearing characteristics than either a single ply or double ply natural leather strap can be made by cementing an outer iiesh layer of one piece of leather onto the esh layer of another piece of leather.V The outer esh layer is formed in the manner illustrated in Figure '10 by sciving the hair and grain layer from the binder layer. The flesh layer including the binding layer from which the grain layer has been removed is then stretched to nearly its elastic limit so that it will have the same stretching characteristics as a grain layer. Furthermore, the stretching of the esh layer will increase its length so' that it will have the same length as the grain layer of the unstretched inner leather strap when folded in a loop. The stretched esh layer is then reversed and placed over the inner leather strap so that its binder layer will overlie the flesh layer of the inner strap as illustrated in Figure 11. The outer stretched iiesh layer is then cemented to the liesh layer of the inner piece to form the composite strap 95. The combining of Vthe two pieces is performed over a curved mold 96 having the vcontour of the loop in the check strap V to be formed and is cemented under'pressure on the form.

"The composite strap 95, as illustrated in Figure 1-1 then has an inner natural leather strap with an inner grain and hair layer A adapted to be contacted by the picker stick 14, an adjacent integral binder layer B, and an integral intermediate unstretched flesh layer C. Adjacent the flesh layer -C of the inner strap is an adhesive layer D, the stretched binder 'layer E of the outer strap and an vintegral stretched esh layer F at the outer periphery.

The inner grain and hair layer A provides the Wearing characteristics required and the outer stretched layer F prevents 'stretching of the inner layer A to prevent it from cracking or breaking. Preferably, we prefer to kuse chrome leather in the outer stretched layer F, but other high strength materials such as rayon or nylon can be used or even unstretched leather.

While several embodiments of the invention are herein illustrated and described, it will be Vunderstood that further changes may be made in the construction and arrangement of elements Without departing from the spirit or scope of the invention. Therefore, Without limitation in this respect the invention is defined bythe following claims. f

'We claim: 5"' .l. A device for checking the motion of a picker stick in a loom comprising asliding element having a smooth bearing surface, alcheck strap, means adjacent the opposite ends of said sliding element for clamping ythe ends of the check strap thereto to form a loop, said last named 'means being adjustable along each end o'f the sliding element to adjust `the length ofthe check strap, a fixed bearing element having anti-friction bearing surfaces .at `each'entl for supporting the lsliding element Vfor free slidlapply a fixed drag thereon,:and means for adjusting the bearing pressure of the central" bearing surface on the sliding element.

A`2.- A device for checking the'motion of a picker stick in a loom comprising a movable unit having a metal rod with a smooth peripheral surface and a looped check strap having its ends attached to the end portions of the rod, a fixed cylindrical bearing sleeve at one side of the movable unitin which the rod slides, said bearing sleeve having anti-friction bearing surfaces atv its ends in which the rod freely slides and a centraljbearing surface engaging the rod between the anti-friction bearing surfaces to apply a drag thereon, and means for varying the pressure applied by the central bearing surface for adjusting the drag on the rod.

3. A device for checking the motion of a picker stick in a lo'om comprising a movable unit having a metal rod with a smooth peripheral surface and a looped check strap having its ends attached to the end portions of the rod, a fixed cylindrical bearing sleeve at one side of the movable unit in which the rod slides, a fixed tensioning device at the other side of the movable unit through which the check strap slides, said bearing sleeve having anti-friction bearing surfaces at its ends in which the rod freely slides and a central bearing surface engaging the rod between the anti-friction surfaces to apply a drag thereon, said tensioning device having a bearing surface engaging the check strap to apply a drag thereon, and means for varying the pressure applied by the central bearing surface and tensioning device for adjusting the drag on the rod and check strap, respectively.

4. A device for checking the motion of a picker stick in a loom comprising a stationary part attached to the loom and a movable part adapted to slide relative to the stationary part, said stationary part comprising a bearing block having a cylindrical bearing sleeve, said movable part comprising a metal rod having a smoothperipheral surface, a looped check strap having its end attached to the ends of the rod for enclosing a picker stick therebetween, said bearing sleeve having anti-friction bushings at each end for supporting the rod for free sliding movement in the sleeve, a central bearing element in the sleeve -between the bushings for engaging the periphery of the rod to apply a drag thereon, means for adjusting the pressure of the central bearing means against the rod, and a resilient element between the adjusting means and bearing element to yieldably engager the latter with the rod with a predetermined pressure.

5. A device for checking the motion of a picker stick in a loom comprising a metal slide bar having a smooth bearing surface, a check strap so formed as to provide a conical shape when the ends are folded inwardly to form a loop, clamping elements mounted on the bar Vadjacent its opposite ends for clamping the ends of the looped check strap thereto, said clamping elements being adjustable along the bar to vary the length of the looped check strap, a fixed Vbearing sleeve having annular bearing surfaces at each end forl supporting the bar for free sliding movement in the sleeve, a central bearing surface in the sleeve between the end bearing surfaces which is deformed relative to the end bearing surfaces for engaging at least one side of the bar to apply a drag thereon, and means for varying the pressure of the central bearing surface on the bar to adjust the drag applied to the bar.

6. A checking device for a picker stick in accordance with claim 2 in which the anti-friction bearing surfaces in the bearing sleeve are of a self-lubricating material of the class including nylon and porous oil irnpregated metals.

7. A checking device for a picker stick in accordance with claim 6 in which the central bearing surface in the sleeve for applying a drag to the rod vis a packing of oil y10 t impregnated leather washers surrounding the-rod-and vven@ gaging the periphery thereof. A 1 e ,i Y8..A checking device for va picker stickin accordance with claim ,7 in which` the resilient means for pressing the'central bearing ,surface into engagement with the rod is a rubberfplate, and the means for compressing the resilient element is a set screw having a threaded engagement with the cylindrical bearing sleeve and engaging the-resilient plate.

. 9. A checking device for a-picker stick in accordance with claimlin which the anti-friction bearing surfaces in the cylindrical bearing sleeve arethe ends of a continuous nylon sleeve extending throughout the length of the bearing sleeve and split at one side on a line parallel to the axls.

10. A checking device for a picker stick in accordance with claim 9` in which the central part of said split nylon bushing is compressed into bearing engagement with the periphery of the rod, and the means for compressing the central part of said split nylon bushing is a resilient plate and set screw.

11. A checking device in a picker stick in accordance with claim 2 in which the cylindrical bearing sleeve has a hollow internally threaded boss projecting therefrom at right angles to the rod, and the central bearing surface engaging the periphery of the rod is a bar in the hollow boss, and a screw in the threaded portion of the boss for engaging the outer end of the bar to press the inner end of the bar against the periphery of the rod. v

12. A checking device for a-picker stick in accordance with claim 11 in which the bar ofvbearing material is of cylindrical form and composed of nylon, and a resilient plug in the hollow boss between the screw and outer end of the nylon bar.

13. A checking device for a picker stick in accordance with claim l in which the bar is in the form of a cylindrical rod having threaded ends, and the means adjacent opposite ends of the bar for clamping the ends of a looped checkstrap 'thereto comprise elements having screw threaded engagement with the threaded ends of-Y the rod for adjustment along the rod to adjust the length of the check strap.

14. A checking device for a picker'stick in accordance with claim 13 in which the means for clamping the ends of a looped check strap comprise metal blocks, bolts for attaching the ends of the straps to the blocks, said blocks having tapped holes extending at right angles of the bolts, the threaded ends of said rods being turned in Athe tapped holes to adjust the length of the check strap,

and lock nuts on the threaded ends'of the rod for clamping the blocks in adjusted position on the rod.

15. A checking device for a picker stick in accordance with claim 13 in which the ends of the check strap have holes to apply the ends of the check strap over the threaded ends of the rod, and nuts on each threaded end of the rod and located at opposite sides of the check strap for clamping the ends of the check strap therebetween, and said nuts being adjustable along the rod at each end thereof to clamp the ends of the check strap in any adjusted position along the rod.

16. A checking device for a picker stick in accordance with claim 13 in which wear straps of short length are provided at the inside face of the check strap adjacent each end for engagement by the picker stick.

17. A checking device for a picker stick in accordance with claim 13 in which resilient plates are provided at each end of the check strap at the outside face thereof to resist bending of the ends of the strap.

18. A device for checking the'motion of a picker stick in a loom comprising a metal slide rod having a smooth bearing surface, a composite leather Vcheck strap having its 'ends folded inwardly to form a loop, clamping element mounted for adjustment along the opposite ends of the 'rod and clamping the ends of the looped check strap thereto, a xed bearing sleeve in which the rod slides l and 4having a central bearing surface for applying a drag on the rod,Y and said composite check strap comprising an inner strap portion' having a grain and'hair surface engaged by the picker stick, an integral intermediate'esh layer outwardly from the grain layer, and a stretched flesh layer of another strap overlying the intermediate vflesh layer and cemented thereto.

19. A composite check strap for a picker stick in a loom comprising an inner leather section having an inner grain and hair surface andan integral outer flesh layer, and an outer prestretched leather section cemented to the inner section comprising a separate `flesh layer, said composite leather check strap being formed on a curved surface to form a loop.

. .12 References Cited in the 1e of this patent UNITED STATES PATENTS t 73,848 Strevell` Jan. 28, 1868 v1,160,040 Carpenter Nov. 9, 1915 1,255,635 Prosser FebrS, 1-918 1,294,238 'Cobb -g. Feb. 11., 1919 1,417,557 Patterson May 30, 1922 2,320,158 Shivell May 25, 1943 2,533,646

Wakeeld Dec. 12, 1950 OTHER REFERENCES 'Dictionary of Leather Termino1ogy, 4th ed.; publication oice, Tanners'Conncil of America, Inc., 100 YGold Y Street, New York, New York.

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